Piston peening device and the like



Aug. 27, 1940. 'r. J. BRUCE PISTON PEENING DEVICE AND THE LIKE FiledAug. 7. 1937 Fla. 2

EN C n m M H P m1 0/ M Patented Aug. 27, 1940 i UNl'iED smrss,

PATENT OFFICE 2 Claims.

It is a well known fact that pistons frequently collapse, becomemisfits, and need expanding and resizing as well as reshaping before theoriginal snug fit is restored and the proper operation of the piston isregained. A piston on which the skirt has collapsed will losecompression, leak lubricant and cause noise.

Machines and devices for reshaping and resizing the collapsed pistonhave been on the market for some time, and they are well known to themachine shop operators and garage men and mechanics. The most successfulones are based on the operation of a cam. actuated trip hammer, it beingvirtually impossible for a mechanic to 5 properly expand, resize andreshape a piston without some tool having a short stroke that can bedirected to a point within the confines of a piston skirt.

One shortcoming of machines now available is 0 the failure to provide ananvil surface adjustable to pistons having what is known as cam shape orirregular surfaces in the outer face of the piston skirt. Since alargeportion of the pistons in use at the present time are so shaped, thedevices 25 in use at the present time for peening purposes are ofnecessity limited in operation to the portion of the piston wall thatwill rest firmly on a fiat support for the whole piston.

One object of the present invention is to pro- 30 vide: an adjustableanvil that will properly support that part of the piston skirt on whichthe peening takes place, whether the piston skirt is uniform incircumference and smooth or is camshaped or irregular.

3* Another object of this invention is to provide a cradle or support ofthe piston, auxiliary to that of the anvil. This cradle is fixed inposition, nonadjustable, but so shaped as to accommodate different sizepistons and cooperate with the anvil 40 to properly support and alignthe piston.

Another object of this invention is to provide a stop or aligning meansfor use in connection with the anvil and cradle, adapted to attach tothe cradle, to prevent longitudinal movement on the cradle, especiallyin a downward direction lengthwise of the cradle.

Other objects and uses of the invention will appear from a more detaileddescription of the drawing and features of invention as hereinafter 50set forth and described.

In the drawing:

Figure 1 shows a front elevation of the device of the present invention.

Figure 2 shows a side elevation of the device 55 embodying the presentinvention, the pulley Wheel showing being fragmentary to allow view ofthe tension indicating means.

Figure 3 is an end View of the cradlemeans on a plane in horizontalalignment therewith, showing also the adjustable anvil means. i:

Figure 4 is a side elevation of the mechanism within the casing orhousing for the device, the casing being eliminated.

1 Figure 5 is a side View of the spring tension adjustment nut, thetension indicator being in place.

Figure 6 is a back elevation of the device of Figure 5.

Figure '7 is a plan view of the tension indicating pointer. Referringmore in detail to Figures 1 and 2,

particularly, and to the other figures as the particular details shownby said other figures are reached for consideration, II shows the casingor housing for the device which is usually a casting or the like; I2isthat portion of the housing that acts as a brace or support for theanvil an cradle assembly.

Number I3 designates the screw head of the bolt shaped anvil I4, as bestshown in Figures 2 and 3. The anvil I4 is threaded through the extendedhousing support 15, and through the cradle Hi. In Figure 3, a piston I1is indicated to show how the cradle and the anvil support it inposition. A smaller piston I8 is indicated by dotted lines, which showsthat the cradle is kept the same, but the anvil must be threaded out tothe proper adjustment in order to secure the correct support andalignment of the piston 3. Other size pistons are handled in a similarway. This entirely does away with the adjustable cradle having hingedsides, and provides a firmer support for aligning the piston.

The anvil l4, while shown in Figure 3 as resting flush against the sideof the piston (the piston is shown only schematically in this drawing)is adaptable to insertion and to irregularities in the surface of thepiston, the anvil being-for this purpose-small enough to enter into anyirregularities on which peening may take place. This provides adequatesupport opposite peening hammer regardless of whether the surface beingpeened is smooth, cam-shaped, or otherwise irregular.

A peening hammer I 9 pivoted about a shaft (withsuitable bearingmeans-not shown) 20, is actuated by the cam 2| which in turn is drivenby connections (not shown) to the pulley wheel 22. This pulley wheel maybe driven by motor pressure of spring 34. tional adjustment may be hadby threading the for which a belt groove 29 is provided, or may beoperated by hand by means of the handle E l.

Referring to Figure 4 and Figures 2, 5, 6, and 7, a spring tension means25 for the peening hammer I9, is adjustable to increase or decrease thepressure or tension on the hammer by adjustment of the knurled lug 126which threads into the upper part ofthe housing II by means of thethreads 21. The lug 26 has a groove around its lower extremity at 23into which sets the semi-circular metal band 29. This band is threadedat 30 to receive the pointer M which is screwed into place through theopening 32 after the lug 26 is in place. Suitable indicating fig-- uresor letters 33 are provided in relation to the pointer 3i so movement upand down of the lug 26, carrying the pointer M, will be indicated. Thiswill necessarily indicate the tension on the spring 25.

To damp the vibration of the spring 25, a second spring 34 fits insidethe spring 25. Tension on this spring 34 is regulated by the adjustablebolt 35 which passes through lug 26 longitudinally. This bolt 35 isthreaded into lug 2t, and adjustment of lug 26 automatically changes theHowever, finer and addibolt 35 in or out.

A means for disengaging the hammer l9 from the cam 2! is provided,thusrendering the hammer inoperative. This same disengaging means mayalso be used to counteract the tension in spring 25 and spring 34(combined) and to thus lighten the stroke of the peening hammer I9. Thisdisengaging means comprises the rod 36 onto which is threaded theadjustable nut 37. This nut 31 is attached to the spring 38, which inturn is attached to the housing or other support 39. This spring 38 is aspring that gains its tension by lengthening, whereas the springs 25 and34 gain tension by compression. Spring 38 is strong enough to offset thesprings 25 and 3 3 when pressure is relieved from the foot or hand pedal40. This pedal 49 is attached to the rod 39. With a little practice askilled operator can exercise very accurate control over the force ofthe blow from the peening hammer I9 by means of the pedal 40.

A set screw M is provided to limit the downward stroke distance of thehammer I9. This is adjustable for different size pistons, and isthreaded into the housing I I on the extension I5.

A lock-nut 42 may be provided to hold the anvil in place.

A stop 43, adjustable with respect to the cradle I6, is provided to holdthe piston against downward displacement endwise. This stop generallycomprises a slotted lug with a set-screw, and may be moved from place toplace on the cradle to accommodate varying sizes of pistons.

I claim:

1. A piston supporting and retaining means for peening purposescomprising in combination a cradle on a supporting member of the pistonpeening machine housing, said cradle being nonadjustable, anvil meanspassing through said cradle and being adjustable vertically'withrelation to said cradle, locking means comprising a lock-nut or the likeretaining said anvil in adjusted position, and an adjustable lug movableon the cradle means comprising a support against horizontal movement ofthe piston, substantially as described. 7

2. A piston supporting and retaining means for peening purposescomprising in combination a cradle, said cradle being non-adjustable,anvil means passing through said cradle and being adjustable verticallywith relation to said cradle, locking means comprising a lock-nut or thelike retaining said anvil in adjusted position, and an adjustable lugmovable on the cradle means comprising a support against horizontalmove- -ment of the piston, substantially as described.

THOMAS JOSEPH BRUCE.

